NGFA/Grain Journal Safety & Health/Grain Quality Conference
New Official Moisture Technology David B. Funk, Ph.D., Chief Scientist Federal Grain Inspection Service August 1, 2012
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History of Official Moisture Meter Approvals • • • •
1937 – Tag-Heppenstall 1960 - Motomco Model 919 1998 - Dickey-john GAC 2100 April 11, 2012 – First UGMA-Compatible moisture meters approved – DICKEY-john GAC 2500UGMA – Perten AM 5200-A. Federal Grain Inspection Service
GIPSA-Certified UGMA-Compatible Moisture Meters Dickey-john GAC 2500UGMA
Perten AM 5200-A
Federal Grain Inspection Service
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What is GIPSA’s Unified Grain Moisture Algorithm (UGMA)? • Very accurate dielectric-type moisture method • Higher measurement frequency (about 150 MHz) • Based on a defined physical parameter—Dielectric Constant • Excellent density correction • Three “unifying parameters” per grain group • A single calibration “curve” for all grain types • Precise, wide-range temperature correction • Calibrated to GIPSA’s standard Air Oven method • “Open”—Available to any manufacturer Federal Grain Inspection Service
UGMA Master System
Agilent E4991A Impedance Analyzer
Master Test Cell Federal Grain Inspection Service
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Eureka! #1: Effectiveness of the Landau-Lifshitz, Looyenga Density Correction
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Eureka! #2: Geometrically-Similar Shapes in VHF Range
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Landau-Lifshitz, Looyenga Density Normalization
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Adjust Slope Parameter for Slope of 6.0 %M per unit dielectric constant in 10-20 % Range
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Adjust Offset Parameter
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Adjust Translation Parameter
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5th-Order Polynomial Equation Number of Samples= 6189
Overall SEC= 0.34 % Moisture
Adjusted Density-Corr. Diel. Const.
9 8 7 6 5 4 3 2
0
5
10
15
20 25 30 35 Reference Moisture
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Unified Grain Moisture Algorithm User Manufacturer GIPSA
Grain Sample
Grain Type
Z* or Γ* Sensor
Instrument Parameters Mass Sensor
Temp. Sensor
Γ* SFG or ABCD Model
Z, d, etc. FF, corr Test Cell Parameters Cell Volume
Sample Mass
εeffective Secondary Corrections ε`r Density Correction ε`density corrected Unifying Parameters
Polynomial Coefficients
Unifying Parameters
ε`unified Polynomial Equation %M Temperature Correction
GROUP ID T Temp. Corr. Parameters
%MTC Moisture Result
Federal Grain Inspection Service
D.B. Funk November 9, 2006
Type-Group Table
Why change to UGMA?
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Improved Accuracy for All Grain Types 2011 Corn Crop GAC 2100
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UGMA
Improved Accuracy of UGMA
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Improved Accuracy of UGMA
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Improved Year-to-Year Calibration Stability
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Corn 0,3
GAC 2100 0,2
UGMA
0,1
0,0
-0,1
1998 1999 2000 2001 2002 2003 2004 2005 2006
-0,2
-0,3
1 yr
Federal Grain Inspection Service
3 yr
Sunflower 0.3
GAC 2100
0.2
UGMA
0.1
0.0
-0.1
1998 1999 2000 2001
2002 2003 2004 2005 2006
-0.2
-0.3
1 yr
Federal Grain Inspection Service
3 yr
Soft Red Winter Wheat 0.3
GAC 2100
0.2
UGMA
0.1
0.0
-0.1
1998 1999 2000 2001
2002 2003 2004 2005 2006
-0.2
-0.3
1 yr
Federal Grain Inspection Service
3 yr
Long Grain Rough Rice UGMA
GAC 2100 0.3
0.2
0.1
0.0
-0.1
1998
1999
2000
2001
2002
2003
-0.2
-0.3
1 yr
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3 yr
2004
2005
2006
Drastically Improved Accuracy on High and Low Test Weight Corn
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GAC 2100 Corn Results—Density Issue Accuracy for 2007-2009 Crops
For range: Samples: Std. Dev. of Diff:
10-36% M 686 0.70% M
Low TW samples yielded low moisture results.
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Corn: Official Test Weight vs. Air Oven Moisture 65
The drastic change in test weight with moisture for normal corn presents special challenges for density correction of corn moisture measurements.
TEST WEIGHT
60
55
50
45
40
9
11
13
15
17
19
21
23
25
27
29
31
AIR OVEN % MOISTURE
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35
37
39
41
43
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Secondary Density Correction Corn Results for UGMA 3
3
Moisture Prediction Error, %M
Before Correction
After Correction
2
2
1
1
0
0
1
1
2
2
3
Normal Corn Low Dens ity Corn
3 0
10
20
30
40
0
Air Oven Moisture, %M
Before
10
20
30
40
Air Oven Moisture, %M
Bias
STD
Slope
After
Bias
STD
Slope
All Samples -0.04 Low Density -0.66
0.46
-0.01
-0.01
0.31
-0.01
0.34
0.00
All Samples Low Density
-0.11
0.32
-0.03
0.36
-0.04
Normal
0.01
0.30
-0.01
Normal
0.09
Federal Grain Inspection Service
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Wider Sample Temperature Ranges 113 °F 103 °F
GAC 2100
UGMA Meters
32 °F
0 °F Federal Grain Inspection Service
“Green” Grain Effects Reduced Moisture Error due to Rapid Drying (%)
Long Grain Rough Rice Rebound
0
5
10 GAC 2100 UGM A 15 10
15
20
25
M oisture Content of the Dried Samp le, M %
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“Green” Grain Effects Reduced Error due to Mixture of Wet and D ry Rice (%)
LGRR Mixt ure Effects 1
0.5
0
0.5 GAC 2100 UGM A 1 15
20
25
30
M oisture Content of the Wet Comp onent, M %
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“Green” Grain Effects Reduced Effects of M ixtures of Wet and Dry Soybeans Moisture Error due to Mixture (%)
2
1
0
1 GAC 2100 UGM A 2 10
15
20
25
M oisture of Wet Component of M ixture (%)
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GIPSA’s Basic Definition of Equivalency • Same technology • Very close agreement among types as well as units of a type • Same calibrations and standardization processes
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UGMA-Compatibility Criteria (1) • • • • • •
NTEP Certification Documented & stable production processes Measurement frequency Standardized test cell design Standardized loading method Standardized measurements – Sample dielectric constant – Sample mass – Sample temperature Federal Grain Inspection Service
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UGMA-Compatibility Criteria (2) • Tight tolerances specified for individual subsystems as well as moisture results • Must use specified mathematics • Units’ agreement with FGIS Master system must meet tolerances in FGIS Regulations – +/- 0.05% M for Headquarters Standard units – +/- 0.15% M for other Official units – Mean difference on medium-moisture HRWW
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UGMA-Compatibility Criteria (3) • All UGMA-Compatible models must be able to use the same check testing process. • A simple check testing process must ensure performance on all grains over full moisture ranges. • Instruments must provide for efficient means of entering calibrations. • Instruments must provide standardized output data stream for printing or networking. Federal Grain Inspection Service
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Excellent Agreement Between UGMA Models
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Excellent Agreement Between UGMA Models
Check Testing Tolerance for Official Moisture Meters
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Far Better Agreement Than Between Different Technologies
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Far Better Agreement Than Between Different Technologies
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UGMA Moisture Meter Implementation Schedule September 1, 2012 • Corn • Soybeans • Sorghum • Sunflower
May 1, 2013 • Wheat • Barley • Oats • Rice (Rough and Processed) • Edible Beans, Peas, Lentils • Canola, Rapeseed, Mustard • Flaxseed • Safflower • Triticale and Rye
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Anticipated Moisture Changes with Transition to UGMA • GAC 2100 and new UGMA –based meters are all calibrated to agree with GIPSA’s air oven method as closely as possible. • Do not expect significant average differences between GAC 2100 and new UGMA-based meters—except: • Low test weight corn moisture values will generally increase: – GAC 2100 reads lower than UGMA by 0.2% per pound per bushel below 57 lb/bu
• High test weight corn moisture values will generally decrease: – GAC 2100 reads higher than UGMA by 0.2% per pound per bushel above 57 lb/bu
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